To put it more succinctly: I agree you should do it by metro area. But you don't - several states have a singular value, or only a value for one city in the sta

To put it more succinctly: I agree you should do it by metro area. But you don't - several states have a singular value, or only a value for one city in the state. The above post has some sources you can peruse on identifying metro areas that need to be assessed in the algo.